This circuit was obtained from documentation from 1968. The transistors used as well as the tunnel diodes are of the time.
In the 1992 publication, this amplifier is announced as having 400 W pmpo. Power transistors should...
This balance control for the channels of a stereo system was found in a 1969 Mullard...
This circuit was obtained from an American 80's documentation. The transistors can be 2N2222 and...